diff options
Diffstat (limited to 'lisp')
| -rw-r--r-- | lisp/ChangeLog | 5 | ||||
| -rw-r--r-- | lisp/env.el | 30 |
2 files changed, 28 insertions, 7 deletions
diff --git a/lisp/ChangeLog b/lisp/ChangeLog index a06055ddb9b..1a312606ee0 100644 --- a/lisp/ChangeLog +++ b/lisp/ChangeLog @@ -1,3 +1,8 @@ +2013-10-10 Stefan Monnier <monnier@iro.umontreal.ca> + + * env.el (substitute-env-in-file-name): New function. + (substitute-env-vars): Extend the meaning of the optional arg. + 2013-10-10 Eli Zaretskii <eliz@gnu.org> * term/w32-win.el (dynamic-library-alist): Define separate lists diff --git a/lisp/env.el b/lisp/env.el index 5618404cb67..044673d5e68 100644 --- a/lisp/env.el +++ b/lisp/env.el @@ -1,4 +1,4 @@ -;;; env.el --- functions to manipulate environment variables +;;; env.el --- functions to manipulate environment variables -*- lexical-binding:t -*- ;; Copyright (C) 1991, 1994, 2000-2013 Free Software Foundation, Inc. @@ -60,30 +60,46 @@ If it is also not t, RET does not exit if it does non-null completion." (defconst env--substitute-vars-regexp "\\$\\(?:\\(?1:[[:alnum:]_]+\\)\\|{\\(?1:[^{}]+\\)}\\|\\$\\)") -(defun substitute-env-vars (string &optional only-defined) +(defun substitute-env-vars (string &optional when-undefined) "Substitute environment variables referred to in STRING. `$FOO' where FOO is an environment variable name means to substitute the value of that variable. The variable name should be terminated with a character not a letter, digit or underscore; otherwise, enclose the entire variable name in braces. For instance, in `ab$cd-x', `$cd' is treated as an environment variable. -If ONLY-DEFINED is nil, references to undefined environment variables -are replaced by the empty string; if it is non-nil, they are left unchanged. + +If WHEN-DEFINED is nil, references to undefined environment variables +are replaced by the empty string; if it is a function, the function is called +with the variable name as argument and should return the text with which +to replace it or nil to leave it unchanged. +If it is non-nil and not a function, references to undefined variables are +left unchanged. Use `$$' to insert a single dollar sign." (let ((start 0)) (while (string-match env--substitute-vars-regexp string start) (cond ((match-beginning 1) - (let ((value (getenv (match-string 1 string)))) - (if (and (null value) only-defined) + (let* ((var (match-string 1 string)) + (value (getenv var))) + (if (and (null value) + (if (functionp when-undefined) + (null (setq value (funcall when-undefined var))) + when-undefined)) (setq start (match-end 0)) - (setq string (replace-match (or value "") t t string) + (setq string (replace-match (or value "") t t string) start (+ (match-beginning 0) (length value)))))) (t (setq string (replace-match "$" t t string) start (+ (match-beginning 0) 1))))) string)) +(defun substitute-env-in-file-name (filename) + (substitute-env-vars filename + ;; How 'bout we lookup other tables than the env? + ;; E.g. we could accept bookmark names as well! + (if (memq system-type '(windows-nt ms-dos)) + (lambda (var) (getenv (upcase var))) + t))) (defun setenv-internal (env variable value keep-empty) "Set VARIABLE to VALUE in ENV, adding empty entries if KEEP-EMPTY. |